// 
// Entify project
//  
// Author:
//       Lauri Taimila <lauri@taimila.com>
// 
// Copyright (c) 2010 Lauri Taimila
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.Reflection;

namespace Taimila.Entify.Attributes
{
	/// <summary>
	/// Not null validator checks is property value null and if it is,
	/// it creates a validation error.
	/// </summary>
	[AttributeUsage(AttributeTargets.Property)]
	public sealed class NotNullValidatorAttribute : ValidatorAttribute
	{	
		/// <summary>
		/// Tests is specified value null.
		/// </summary>
		/// <param name="property">
		/// Property which value is validated.
		/// </param>
		/// <param name="value">
		/// Value to be validated. <see cref="System.Object"/>
		/// </param>
		/// <returns>
		/// ValidationError or null. <see cref="ValidationError"/>
		/// </returns>
		public override ValidationError ValidateValue(PropertyInfo property, object value)
		{
			if(value == null)
			{
				return new ValidationError(ValidationErrorReason.ValueIsNull, property, property.Name + " is not allowed to contain null value.");
			}
			else
			{
				return null;	
			}
		}
	}
}
